This invention relates to a method for preparing magnetic fluids, and, more particularly, to a method for preparing stable water base ferromagnetic fluids.
The magnetic fluid is a stable suspension of magnetic particles with a particle size, normally less than 300 A, in a carrier fluid. The suspension does not settle out under the influence of gravity or even of a magnetic field. The magnetic fluid responds to an applied magnetic field as if the fluid itself had magnetic characteristics.
Magnetic fluids have been used in various fields; for example, pumps, bearings, seals, specific gravity meters, or recovering oil spills.
Known and used magnetic fluid are usually stable suspensions of magnetic particles in a non-polar solvent. On the other hand, the only known method to prepare a polar solvent, such as water, base magnetic fluid is a grinding method. The resultant suspension produced by the grinding method is not sufficiently stable to satisfy the needs for various application.
If it is possible to produce stable water base magnetic fluids, economical magnetic fluids would be provided because of the low cost of the base solution.